Penicillin is normally given either as injection or in the form of mixture. However both are unsuited for children, either because they are afraid of being pricked or because they dislike the taste which may result in vomiting.
Also adults may have difficulty ingesting penicillin orally, and treatment with injections can only be carried out by specially trained personnel. Consequently, there is a need for a form of penicillin which can be administered rectally.
Over the years many attempts have been made to prepare an efficient suppository with penicillin. Thus, from Danish Patent No. 138,975 is known a rectally administrable penicillin preparation which contains sulbenicillin dialkalimetal salt or carbenicillin dialkalimetal salt in an oil or fat basis containing a non-ionic surface active agent.
From German published application No. 2,619,756 is known a rectally administrable penicillin preparation which contains 6-[D-(-)-.alpha.-(4-oxo-4H-thiopyran-3-yl-carboxamido)-p-hydroxyphenyl acetamido]-penicillanic acid in an oily suppository basis.
From British Patent No. 1,462,399 is known a rectally administrable penicillin preparation which contains cephalexin in an oil soluble or water soluble suppository basis which may be placed in a soft gelatin capsule.
Finally, K. Backe-Hansen in Scandinav. J. Clin. & Lab. Investigation, 170-173, 9, 1957, has described experiments with rectal absorption of benzylpenicillin in which was used a suppository basis of triglycerides containing benzylpenicillin sodium together with sodium lauryl sulphate, the latter supposedly having the effect of lowering the surface tension so that a better contact between the penicillin and the mucosa of the rectum is obtained and of inhibiting the decomposition of penicillin by penicillinase in rectum. The investigation has never resulted in a commercial product. The reason for this may be that the stability of pencillin in cast suppositories is not always good, that cast suppositories must be able to melt at body temperature which renders them rather temperature sensitive, and that production costs are high.